[PATCH] Better __ashlDI3, __ashrDI3 and __lshrDI3 functions, plus fixed __bswapsi2 function

[Jeff Law]

On 11/24/20 8:40 AM, Stefan Kanthak wrote:
> Andreas Schwab wrote:
>
>> On Nov 24 2020, Stefan Kanthak wrote:
>>
>>> 'nuff said
>> What's your point?
> Pinpoint deficiencies and bugs in GCC and libgcc, plus a counter
> example to your "argument"!
> I recommend careful reading.
Umm, you should broaden your horizons.  The world is not an x86.  I'm
pretty sure Andreas was referring to non-x86 targets.

As Jakub has already indicated, your change will result in infinite
recursion on avr.  I happened to have a cr16 handy and it looks like
it'd generate infinite recursion there too.

On other targets the routines you're changing won't be used because they
either have 64 bit shifts or the compiler can synthesize them from other
primitives that are available.

It's pointless to keep arguing on the shift stuff.  What you've
submitted is fundamentally wrong in the context of gcc's libgcc2
routines.  It's that simple.  If you keep arguing about it you're likely
just going to annoy those who can help you to the point where they won't
bother.

I think the bswapsi2 change will go forward, but it needs to be tested.

jeff